G76 - A little O/T

[Randy Morton @ Clem Industrial]

Hey all,

 

Just curious, I have a fanuc 18MC control, and I am using G76 to bore a hole, but when the spindle orients it will drag along the part surface. It is a 2 cutter boring head, and the only shift I am able to do is onp the X with this control. So what I am wondering is if there is a letter control that is not listed in the book to do (hypethically) the following...

 

G76 blah blah blah

when end of bore is reached the spindle orients

then turn the spindle 90 deg (for example)

 

Can this be done? Is there a better boring cycle to assist with this?

[PeterM]

If you are using a two cutter head I can't see how you can shift without dragging the tool along the bore, why not just use a G85 boring cycle. G86 will stop at the bottom and rapid out but it will probably still make a line in the bore.

_____________________

Peter Martin

mcam 3... - x mr2 - mill level 3

Senior Programmer/Milling Supervisor

Preci Mfg.

400 Weaver St. Winooski VT 05468

email [email protected]

[Rick Henrickson 65]

I think your only option is to use G85 bore in bore out you don't have any room to move off the bore with a twin head.

[Randy Morton @ Clem Industrial]

That's kinda what I was figuring....sad, but seems like the only way as yet.

 

Thanks guys!

[Matt Berube at Ferron Mold]

quote:

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the only shift I am able to do is onp the X

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There should be a parameter to make it shift in Y instead...

 

Of course that still won't solve the issue of having a twin boring head...

[Quickmike]

On the twin boring head are both the tips set at the same radius? Or is one a rougher and one a finisher?

[crazy^millman]

I would skip the boring cycle make a sub or macro program and yes doulbe heads can be cleared just not as much as a single head but if you got .001 you got a mile in my book.

 

HTH

[Mgrenier]

quote:

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and yes doulbe heads can be cleared just not as much as a single head but if you got .001 you got a mile in my book.

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Even if the 2 inserts are on the same diameter?Could you please explain how as this might be helpful to us.

[Randy Morton @ Clem Industrial]

My twin bore head is soley for roughing. Both 'certs are at the same diameter. As for the custom macro, I have not done too much with macros yet (all be it, I could just use a G1 and similar). My part is a gear case with 2 bores that overlap each other by about 30%, so I have lots of room to shift it either up or down if my inserts were at 90deg. to the M19 orient....

[3rdstring]

quote:

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M19 will orientate. Add Pxxx.xxx with M19 to orientate to specific angle. Use this for clearance for the air line.

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From Trevor in another thread.

 

They were talkin about a Hass, don't know if that'll work on a FANUC controll or not.

[Paul Kingsley]

Most machines with fanuc controls will use par. 4077 for spindle orientation position. If you have the G10 option on your control you can simply put a statement before your canned cycle saying G10 L50 N4077 R(value of par 4077 plus or minus 900)then G11 on the next line.This will shift the orientation position by 90 deg. in the cw or ccw direction. 1800 will shift by 180 deg. etc.etc. Be sure that after your canned you use the same statement to shift 4077 back to it's original value, or if the machine has a tool changer it "will" wreck it.

[machtek]

quote

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My twin bore head is soley for roughing.

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If it is used for roughing, set the dia. smaller and bore in and out using a slightly faster feed rate.

 

quote:

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and yes doulbe heads can be cleared just not as much as a single head but if you got .001 you got a mile in my book.

 

_________________________________________________

 

How can a double head be cleared without changing dia. of head before retract?

 

[Guest]

quote:

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How can a double head be cleared without changing dia. of head before retract?

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If it is a double head set with a roughing/finishing configuration it can.

 

The rough side will cut 1 size(undersize) the finish will cut finish size. You orienate so the finish side is backed off, you have a bit of clearance between the rough side and the finish bore.

[machtek]

Also I guess he could be roughing at different dia's: one insert rough the other intermediate rough. Also the boring head could be truned 90 deg in the mill holder.